The present invention relates to the field of polishing pad conditioners, and more particularly to an improved end effector for conditioning pads used to polish the surface of semiconductor wafers or semiconductor devices, glass substrates and the like.
In the semiconductor industry, a semiconductor wafer is planarized or xe2x80x9cpolishedxe2x80x9d using a chemical mechanical polishing apparatus that presses a surface of the wafer against a surface of an abrasive pad and that moves the surface of the wafer relative to the surface of the abrasive pad. As polishing continues, the surface of the abrasive pad may become compacted and lose its abrasive quality. Such compaction reduces the quality and efficiency of the polishing process. Accordingly, the abrasive pad is conditioned or roughened (in situ or ex situ) via a device known as a pad conditioning end effector. Typically the end effector comprises one or more diamond crystals held by mechanical means (e.g., by screw type holding mechanisms). During pad conditioning the diamond crystals are pressed against the surface of the polishing pad and are moved relative to the surface of the polishing pad. When crystals are held via mechanical means, the crystals are necessarily relatively large and provide less than optimal pad conditioning. Accordingly, an improved pad conditioning end effector is needed.
To overcome the drawbacks of the prior art, an inventive end effector is provided for conditioning a polishing pad. The end effector comprises a backing plate, a matrix material adhered to a first surface of the backing plate, and a plurality of crystals embedded in the matrix material an amount sufficient to prevent the plurality of crystals from becoming dislodged from the matrix material during pad conditioning. The plurality of crystals have an absolute crystal height distribution that may be skewed toward zero. Methods are also provided for forming the inventive end effector.
Other features and aspects of the present invention will become more fully apparent from the following detailed description of the preferred embodiments, the appended claims and the accompanying drawings.